4&#39;-sulpho-2-benzoyl-5-nitro-benzoic acid and process for making same



Patented June 16, 1931 i IVAN GUIBELMANN, HENRY J. WEILAND,

WAUKEE, WISCONSIN, A$$IGNORS, BY MESNE ASSIGNMENTS, TOTQ'EWPORT CHEMI- 1,s10,0es

FATE mm AND OTTO STALLMANN, SOUTH 'IMIL- CAL CORPORATION, A CORPORATION OF DELAWARE I I 4'-sULPHo-2-BENzoYn-5-NITRoamazon} Aorn AND PROCESS non MAKING SAME No Drawing. Application filed July 2,

This invention relates to 4b -sulpl1o-2- i benzoyl--nitro-benzoic acid and to a process for making the same.

It is an object of this invention to provide a simple and economical process for preparing 4L-sulphO-Q-benzoyl-5-n1tro-benzo1c acid,

which is an intermediate from which valuable dyestufis may be prepared.

Other and further important ob ects of this invention will become apparent from the disclosures in the following description and appended claims.

e have now discovered that ei-sulpho-obenZoyl-benzoic acid, which has been described in our co-pending application Serial No. 203,265, filed July 2, 1927, can be nitrated under certain conditions to i sulpho-2-benzoyl-5-nitro-benzoic acid. We have proved that the N0 group enters in meta position SO M in which M represents hydrogen or a metallic radical such as for example sodium. v

sulpho-2-benzoyl-5-nitro-benzo1c a c 1 d (mono sodium salt) is a white crystalline powder, easily soluble in water, imparting to it a light yellow color. It is likewise easily soluble in dilute caustic soda, sod um carbonate and ammonia solutlons It IS, how- Serial No. 203,259.

can be recrystallized from hot water contain- 7 ing a small amount of sulphuric acid in the form of small white needles, v

- Without limiting our invention toany particular procedure,the following example, in

which pa-rts b'y weight are given, illustrates the applicationof our invention in the preferred form": f

328 parts of 47-sulphogo-b'enzoyl-benzoic acid (monosodium'salt) are dissolved in 650 parts of sulphuric acid monohydrate at to C. Tothis solution is added over a period of .6 to 8 hours a mixture consisting of 100 parts of mixed acid analyzing 70% HNO 22% H,S O 8% H 0, and 3-80 parts of 25% oleu'm,keeping the temperature at 15'to 20? C. The temperature is then raised to to 38 C. and held'iat'this'temperature fora'bout 3 hours; The nitration mass is then slowly run into a mixture of 2500 parts of ice and 1500 parts of water, and the nitrated product salted out with about 1000 parts of common. salt. The product, 4-sulpho-2-benzoyl-5- nitro-benzoic acid (mono sodium salt), preoipitates and is filtered off, washed with cold water and dried.

! Instead of starting with themono-sodium salt, as in theabove exampleireither the free acid or the. di-sodium salt maybe employed.

Similarly, thecomposition ofthe nitrating I mixed acidmay bev'aried Within reasonable l11n1ts.[

We are aware that numerous of the e process may be varied through a wide range without departing from the principles of this invention, and we therefore, do not purpose limiting the patent'granted hereon, otherwise than necessitated by theprior art.

We claim as our invention: Y 1. The process for preparing 4-sulpho-2- prises reacting a solution of the monosodium salt of 4;sulpho-o-benioyl-benzoic acid in sulphuric acid emonohydrate with a nitiating mixed acid, diluting up the nitration mass with water, salting out and filtering oil the product.

3. As a new article of manufacture, 4:- sulpho-2-benzoyl-5 nitro-benzoic acid, having in the form of the free acid most probably the following chemical constitution,

GOOH

li metal which compound may be prepared by treating a. sulfuric acid solution of 4 sulpho-o-benzoyl-benzoic acid with a nitrating agent.

7. As a new article of manufacture, a' 4- sulpho-2-benzoyl-5-nitro-benzoic acid compound having, in the form of the free acid, the following formula:

SOJI

which may be prepared by treating a solution of 4-sulpho-o-benzoyl-benzoic acid in sulfuric' acid monohydrate with a nitrating acid consisting of a mixture of nitric acid,

22% sulphuric acid and 8% water, together with a quantity of 25% oleum, at a temperature ranging between 15 and 38 C.

In testimony whereof we have hereunto subscribed our names.

IVAN GUBELMANN. HENRY J. WETLAND. OTTO STALLMANN. 

